import com.google.caliper.Param;
import com.google.common.cache.LocalCache.Segment;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Benchmark for {@code LocalCache.Segment.removeEntryFromChain}.
 *
 * @author Charles Fry
 */
@SuppressWarnings("CheckReturnValue")
@NullUnmarked
public class ChainBenchmark {

  @Param({"1", "2", "3", "4", "5", "6"})
  int length;

    // alone
    assertThat(segment.removeEntryFromChain(entryOne, entryOne)).isNull();

    // head
    assertThat(segment.removeEntryFromChain(entryTwo, entryTwo)).isSameInstanceAs(entryOne);

    // middle
    ReferenceEntry<Object, Object> newFirst = segment.removeEntryFromChain(entryThree, entryTwo);
    assertThat(newFirst.getKey()).isSameInstanceAs(keyThree);

    // alone
    assertThat(segment.removeEntryFromChain(entryOne, entryOne)).isNull();

    // head
    assertThat(segment.removeEntryFromChain(entryTwo, entryTwo)).isSameInstanceAs(entryOne);

    // middle
    ReferenceEntry<Object, Object> newFirst = segment.removeEntryFromChain(entryThree, entryTwo);
    assertThat(newFirst.getKey()).isSameInstanceAs(keyThree);

      if (valueReference.isLoading()) {
        valueReference.notifyNewValue(null);
        return first;
      } else {
        return removeEntryFromChain(first, entry);
      }
    }

    @GuardedBy("this")
    @Nullable ReferenceEntry<K, V> removeEntryFromChain(
        ReferenceEntry<K, V> first, ReferenceEntry<K, V> entry) {
      int newCount = count;
      ReferenceEntry<K, V> newFirst = entry.getNext();